Aquarium thermometer



FIG. 1 is a top plan view of an aquarium thermometer showing our new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a left side elevational view thereof, the right side being a mirror image thereto;

FIG. 4 is a rear elevational view thereof;

FIG. 5 is a bottom plan view thereof. 

The ornamental design for an aquarium thermometer, substantially as shown and described. 